1. Field of the Invention
The present invention relates generally to a data processing apparatus and method for transposing horizontally input image data into vertically arranged data and providing the vertically arranged image data to a scanning apparatus that requires vertically arranged data. More particularly, More particularly, the present invention relates to a data processing configuration and method capable of receiving horizontally input image data and supporting the high-speed operation of a spatial optical modulator device used in a high definition television and so forth using a memory having a limited data input/output speed.
2. Description of the Related Art
As shown in FIG. 1a, in typical High Definition Television (HDTV) application, input image data is arranged in a horizontal direction. A Spatial Optical Modulator (SOM) device, as shown in FIG. 1b, is provided with 1080 micromirror devices that are vertically arranged so that it is adapted to scan and display 1080 pieces of image data in a horizontal direction at one time.
The present invention relates to an apparatus and method for receiving horizontally arranged data as shown in FIG. 1a and providing a vertically arranged data array as shown in FIG. 1b. 
If it is assumed that each frame of image data is composed of K×L bytes (row length: K bytes, column length: L bytes), the apparatus and method of the present invention provides data on a K×N-byte-at-a-time basis.
In a universal HDTV standard, each frame of image data has a row length (K) of 1920 pixels and a column length (L) of 1080 pixels, and each pixel is generally composed of three bytes, the three bytes corresponding to Red, Green and Blue (RGB) signals, respectively.
An SOM device used for image scanning for a universal HDTV is a device for outputting an HDTV-level image, in which 1080 micromirror cells are arranged in a line, so that the SOM device is adapted to scan and display image data in a horizontal direction. Accordingly, the SOM device requires 1080 pieces of vertically arranged data to scan each frame of image data that is composed of 1920×1080 pixels.
FIG. 2a shows the structure of each frame of image data that is composed of 1920×1080 pixels. The image data shown in FIG. 2a is horizontally input from the outside in the sequence of (0,0), (0,1), (0,2), (0,3), . . . . However, since the SOM device requires 1080 pieces of vertically arranged data, the input image data must be transposed from a horizontal arrangement to a vertical arrangement, as shown in FIG. 2b. 
FIG. 3 is a block diagram of a system for an HDTV that is implemented using the conventional SOM device. The system shown in FIG. 3 includes an SOM device 11, an SOM driver 12 for driving the SOM device 11, a flash memory 13 for storing a reference table to correct the characteristics of the SOM device 11, a memory 14 for storing image data, a galvanometer mirror scanner 15 for scanning an image to a screen and an SOM controller 16 for transposing the arrangement of the rows and columns of the image data and transmitting a resulting image to the SOM driver 12, and controlling the galvanometer mirror scanner 15.
Image scanning schemes for HDTVs are classified into a three-panel scheme and a one-panel scheme according to the number of electron guns used. The three-panel scheme employs three driver devices, the three driver devices taking charge of RGB colors, respectively, and three SOM devices, the three SOM devices being allocated to the three driver devices, respectively. In contrast, the one-panel scheme employs one driver device and one SOM device. Since the one-panel scheme generates RGB signals using only one SOM device, it allows the number of SOM devices, the number of SOM driver Integrated Circuits (ICs) for driving the SOM devices and the size of an optical system to be reduced to about ⅓ of those for the three-panel scheme so that an HDTV can have a simple structure and thus can be manufactured at low cost.
However, in order to implement HDTV using the one-panel scheme, the operational speed of the SOM device must be about 2 or 3 times faster than that of the three-panel scheme, and a driver for driving the SOM device and an SOM device controller for transferring data must also operate at such a speed.
In an apparatus and method for transposing data used in the application of an HDTV and providing the transposed data to an SOM device, a memory capable of storing data corresponding to at least one frame of image data is required to transpose the arrangement of the rows and columns of data.
In order to store one frame of image data at HDTV-level resolution (1920×1080 pixels), at least 2×3 Mbytes, which are too large to be implemented in an IC, are required. Accordingly, in order to store data, an additional memory, such as external memory, is required.
In order to store 1920×1080 pixels on a 1×3-byte-at-a-time basis at a reference frequency of 60 Hz in real time, a write operation must be performed at about 150 MHz. In particular, since the SOM device of the one-panel scheme outputs all the RGB signals using only one SOM device, it must operate at a speed about 2 or 3 times faster than that of the three-panel scheme at the time of transmitting data to the SOM controller.
In the case of using an external memory, the external memory has a limitation in increasing a data input/output speed, so that the external memory cannot guarantee operational reliability when the above-described fast operational speed is required, and a possibility that noise is caused by high-speed operation increases.
Accordingly, a data processing scheme for performing the high-speed operation of the SOM device without increasing the data input/output speed of the external memory is required.
Japanese Unexamined Patent Publication No. 5-207264 discloses an image memory device capable of transposing the arrangement of the rows and columns of image data read by a scanner in a facsimile or the like. The above document discloses a configuration for transposing the arrangement of data in such a way as to record data along a column direction using a row data buffer at the time of recording data in a memory array and to read the data along a row direction using a column data buffer at the time of reading the data. However, the memory configuration disclosed in the above document has limitations in that it cannot be used to process moving images and cannot be applied to applications that require high-speed data processing, such as an HDTV.